In the production of plate glass, in order to convey glass ribbon in a molten state, a heat-resistant roll provided with a roll part is used. In order to produce high-quality plate glass that is suited to a liquid glass display or a plasma display, it is required to suppress unfavorable effects exerted on glass ribbon by this heat-resistant roll as much as possible.
Under such circumstances, Patent Documents 1 to 3 propose polishing of the surface of the roll part as finishing of a heat-resistant roll. Patent Document 4 describes smoothing of the surface with water after polishing.